The 548 area code belongs to the Ontario (ON) province of Canada and some of the locations covered are Brantford, Sarnia and more:
|Province||Larger cities in area code 548||Time Zone|
|Brantford, Cambridge, Chatham, Guelph, Kitchener, London, Sarnia, Windsor
Current time is
|-- overlays area codes 519 and 226 --|
Initially scheduled to enter service in 2015, the new 548 area code, announced by the Canadian Numbering Administrator (CNA) as the relief method for Southwestern Ontario NPAs 519 and 226 was eventually activated one year later on June 4, 2016. There will be no changes in the way residents in the area served by these area codes will dial calls (the change took place back in 2006 when area code 226 was overlaid on NPA 519). As a reminder, all local and toll calls within the newly created overlay complex will be dialed using 10 and 11 digits respectively.
See official announcement and area code map (PDF document)